   [id source]
   (let [content (collect-bytes source)]
     (when (pos? (count content))
-      (Block. id (count content) content nil nil nil))))
+      (->Block id (count content) content nil nil nil))))
 
 
 (defn read-block

  given the id and size directly, without being checked."
  ^blocks.data.Block
  [id size reader]
  (Block. id size nil reader nil nil))


(defn literal-block

;; ## Constructors

;; Remove automatic constructor function.
(alter-meta! #'->Block assoc :private true)


(defn lazy-block
